Iran seemed finally to be backing away from a confrontation with America and Europe over its nuclear programme, as senior officials and politicians in Tehran said yesterday that proposals put forward last week might form the basis for negotiation.

State-run television reported that President Mahmoud Ahmadinejad had told UN Secretary-General Kofi Annan that a deal was feasible, provided Tehran kept a minimum right to atomic energy.

Foreign Minister Manouchehr Mottaki added that he welcomed unconditional talks with all parties involved, including the United States.

'We think that, if there is goodwill, a breakthrough to get out of a situation [the EU and US] have created... is possible,' Mottaki told a press conference. 'We think the views we will present our partners could prepare the ground for a comprehensive understanding.' However, Mottaki added that Iran would not cease uranium enrichment, a Western precondition for talks.

Last week's diplomacy showed no signs of slowing this weekend. The EU's foreign affairs chief, Javier Solana, is due to arrive in Tehran today or tomorrow to hand over the most recent negotiating offer - the first backed by all major Western powers. Details of the deal have not been made public, but it is believed to include massive assistance with a civilian nuclear programme and a series of major trade concessions. If Iran rejects it, there is the possibility of sanctions, and eventually of military action.

There was no immediate reaction from the Foreign Office to the statements of Ahmadinejad and Mottaki, but the new line was privately welcomed by Western diplomats. 'It's very early days but hopefully it's a vindication of our strategy,' said one Paris-based diplomat.

Others, however, pointing out Iran's labyrinthine command structure, said that comments from the president and the foreign minister might not be the last word. 'There's a good chance that they are just playing for time,' said one.

Others doubt the good faith of the Americans, who last week said they were prepared to negotiate directly with Iran for the first time in 27 years. 'The Americans have learnt the lessons of Iraq and are looking to build as broad an alliance as possible to give them the greatest possible room for manœuvre later on,' said one analyst.

Iran announced in April that it had enriched uranium for the first time. Enrichment can produce either fuel for a nuclear reactor or material for a warhead - but tens of thousands of centrifuges are needed to do either on a large scale.

Iran, which says it intends to move toward large-scale uranium enrichment by late 2006, seems to have in effect reached the end of a period of massive advance and investment in its nuclear programme. It may well be the case that scientists have advised the political leadership that a pause - during which negotiations could continue - would not cause a real delay.

Iran maintains that, as a signatory to the Nuclear Non-Proliferation Treaty, it has the right to enrich uranium for peaceful purposes - such as the production of reactor fuel - but has also occasionally indicated that it may suspend large-scale uranium enrichment if that helped to ease international tension.